Control apparatus



NOV. 4, 1941. w C MCWHIRTER 2,261,3 96

CONTROL APPARATUS Filed Jan. 30, 1940 2 Sheets-Sheet l William HIS ATTORNEY Nov. 4, 1941. w. c. MCWHIRTER CONTROL APPARATUS 2 Sheets-Sheet 2 Filed Jan. 30, 1940 HIS ATTORNEY Patented Nov. 4, 1941 UNITED STATES PATENT OFFICE CONTROL APPARATUS Application January 30, 1940, Serial No. 316,387

2 Claims.

My invention relates in general to control apparatus, and in particular to control apparatus utilizing manually operable levers. More particularly, my present invention relates to time release mechanism for use in connection with the levers of interlocking machines employed in railway signaling systems.

In interlocking machines of the type referred to, time release mechanism is applied to selected ones of the levers to insure that under certain conditions a predetermined time interval will elapse between the operation of these levers and other levers which are mechanically interlocked therewith, to prevent a dangerous traffic condition. For example, a time release mechanism may be applied to a signal lever which controls the signals over conflicting routes, and which is mechanically interlocked with a switch lever for controlling a switch forming part of the routes, to preclude the possibility of the switch being thrown under a train, or a collision or derailment occurring, due to an operator changing a route by reversing the switch as a train approaches after the distant signal has been accepted. When a release mechanism is thus applied to a signal lever, the operator having once set up a route for an approaching train and having operated the signal lever to clear the signal for the route, may return the signal lever to its normal indication position which puts the signal to stop, but he is prevented from returning the signal lever to its full normal position so as to release the mechanical looking for the switch lever, until after the time release mechanism has operated a contact to energize an electric lock which is provided on the lever.

. Heretofore, the time release mechanism has usually been operated by a spring actuated clockwork, the spring of which is maintained in its normally wound-up condition by cam action in response to movement of the associated lever to either extreme position. With release mechanism of this type, the mechanical effort required to wind the spring, particularly in large interlocking machines where the locking imposes a considerable load on the levers, adds enough additional load to the levers to be objectionable. Furthermore, with mechanisms of this spring actuated type, the amount that the spring has to be wound up for different releases, and hence the load exerted on the various levers by the time release mechanisms, varies considerably depending upon a number of conditions too nuof the various levers results in an objectionable operating condition.

One object of my present invention is to provide a time release mechanism which will eliminate any undesirable load on the levers due to the release mechanism.

In accordance with one form of my invention, the above object is accomplished by utilizing electric motor means in place of a spring actuated clockwork to operate the timing contact of the mechanism. In this motor driven mechanism, the motor means is connected with the contact operating rod through the medium of a friction clutch which transmits only enough torque to the operating rod to close the timing contact, and which is adapted to be slipped to restore the operating rod to its initial or starting position after the operating rod has been moved to its contact operating position by the motor. The restoration of the operating rod to its normal position is effected through the medium of a cam operated by the lever in a manner similar to that usually utilized to wind the spring of i the clockwork mechanism. The force required merous to mention, and this difference in action to slip the clutch will be substantially less than that required to wind the clockwork mechanism, and it follows therefore that my invention results in a considerable reduction in the load imposed on the lever by the timing mechanism. The motor means may comprise a direct current motor, or an alternating current motor such as the well-known Telechron motor, or it may comprise a stepping magnet supplied with current impulses from a code transmitter over contacts of the lever which are closed when the lever is moved to the proper position to render the time release mechanism effective to control the lever.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

Time release mechanisms embodying my in vention are an improvement upon the mechanism shown in Letters Patent of the United StatesNo. 2,193,906, granted on March 19, 1940, to John W, Logan, Jr.

I shall describe two forms of time release mechanisms embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings. Figs. 1 and 2 are front and side vertical sectional views, respectively, showing time release mechanism'embodying my invention applied to an interlocking machine lever, certain of the parts being broken away or removed to better illustrate the construction of the remaining parts. Fig. 3 is a detail side view of a portion of the time release mechanism as it appears when viewed from the right in Fig. 2. Fig. 4 is a detail sectional view taken on the line IV-IV of Fig. 3. Fig. 5 is a diagrammatic view showing a typical circuit for controlling the time release mechanism shown in the preceding views. Fig. 6 is a view partly in section and partly diagrammatic showing a modified form of the time release mechanism together with a typical control circuit therefor, and also embodying my invention.

Referring first to Figs. 1 and 2, the time release mechanism is designated as a whole by the reference character TRM, and in the particular form here illustrated comprises a suitable frame consisting of a top plate I and a bottom plate 2 secured to the opposite ends of a pair of spaced side plates 3 and 4. The top plate is adapted to be attached to the under side of the table or frame 5 of an interlocking machine by means of screws 5, and is provided with a through opening 1 which slidably receives the upper end of an operating rod 8. The operating rod 8 is threaded adjacent its lower end through a nut 9 which is pivotally connected with a bifurcated crank arm H secured to a shaft I2 journalled in the side plates 3 and 4. The lower end of the rod 8 is squared for engagement by an adjusting key (not shown) by means of which the rod may be rotated in the nut to effect vertical adjustment of the rod relative to the nut. A look nut I3 is screwed onto the rod below the nut 9 for maintaining the rod in its adjusted position.

The shaft 12 is operatively connected through a friction clutch F mounted thereon and suitable reduction gearing, with an electric motor M.

The friction clutch F may assume any one of a variety of forms, but in the particular form here illustrated this clutch comprises a friction disc l3 disposed between two pressure plates 14 and 15, the one of which I4 is fixed to the shaft, and the other of which mounted on the shaft in such manner that it is free to both rotate and slide axially along the shaft. The clutch also comprises a compressed coil spring [6 which surrounds the shaft I2 between the pressure plate l5 and a nut I1 screwed onto the shaft, and which spring serves to constantly bias the movable plate IE to the longitudinal position on the shaft in which the two pressure plates and the friction disc frictionally engage each other. The force which can be transmitted by the clutch without slipping will, of course, depend upon the compressive force exerted on the plate l5 by the spring l6, and can be readily varied by adjusting the nut I! to different longitudinal positions on the shaft to change this pressure. This pressure will be so adjusted that operation of the motor will be effective to raise the operating rod, but that the operating rod can be moved downwardly without causing operation of themotor. That is to say, downward movement of the operating rod will cause the clutch to slip.

The reduction gearing which connects the clutch with the motor M may also assume any convenient form. As here illustrated, this gearing comprises a spur gear l8 formed integrally with the pressure plate 15 and meshing with a spur pinion l9 secured to one end of the shaft 20. The shaft 29 is journalled in the plates 3 and 4, and has secured thereto, in addition to the pinion I5 is loosely i 19, a spur gear 2| which meshes with a pinion 22 mounted on the motor shaft. The motor M is mounted on the plate 3 and as here illustrated is a direct current variable speed motor. However, this motor can, if desired, be a self starting alternating current motor such, for example, as the well-known Telechron motor.

The upper end of the operating rod 8 is operatively connected by means of a suitable coupling 30 with the lower end of a connecting rod 3! in such manner that the connecting rod will be constrained to both rotate and move vertically in response to corresponding movements of the operating rod. The connecting rod 3| extends upwardly with some clearance through the reduced lower end of a bearing sleeve 32 and is adjustably crewed into the lower end of a tubular contact operating member 33 which is mounted for vertical sliding movement within the enlarged upper portion of the bearing sleeve. The bearing sleeve 32 is formed integrally with a guide member 34 and extends downwardly through the interlocking machine frame 5 and has its lower end disposed in the socket formed by the upper end of the opening I, whereby the parts are maintained in the proper vertical alignment. Vertical displacement of the bearing sleeve and guide member is prevented by means of a nut 35 which is screwed onto the lower end of the enlarged portion of the sleeve in engagement with a spacing sleeve 36.

Formed on the upper end of the contact operating member 33 is a vertical arm 33a which slides in a vertical slot 340. provided in the guide member 34. The arm 33a serves to maintain the contact operating member 33 in a fixed angular position relative to the guide member and the bearing sleeve, and also carries a bracket provided at its upper end with an offset portion to which an insulating strip 6| is attached. The insulating strip BI is provided with a conducting strip 53 which, when the contact operating member is moved to an extreme upper position, connects a contact finger 63a with a contact finger 63b to close a contact 53a-6363b. The contact fingers 63a and 63b are secured by means of terminal posts 64a and 54b to an insulating block 65 mounted on an extension 66 of the guide member 34.

The insulating strip 6| also serves when the contact operating member 33 is moved to its upper position to engage a flexible contact finger 61 and move it out of engagement with the fixed contact finger Bla to open a contact 6'l6la. The fingers 67 and 61a are secured by means of terminal posts 68 and 68a to the insulating block 65. The contact 6l6la is intended to be included in the control circuit for the motor M, and this contact provides a means for interrupting the motor circuit when the contact operating member has been moved to its upper position, as will be made clear presently.

The guide member 34 is provided in addition to the slot 34a with another slot 34b which intersects the slot 34a at right angles, and secured to an interlocking machine lever 38 for swinging movement between two extreme positions within this latter slot is a segment 10. This segment is provided at each end with a cam H which cooperates with a cam follower 12. The cam follower 12 is mounted for vertical sliding movement within the slot 34a at one side of the arm 33a on the contact operating member 33, and is secured to the upper end of a plunger 13 which extends with clearance into the upper end of the contact operating member and engages the upper end of the connecting rod 3|.

In explaining the operation of the time release mechanism as a whole, I shall assume that the contact operating member 33 has been moved to its upper extreme position in which the contact 63a--6363b is closed, and the contact 616'la is open, as shown in the drawings, and that the lever 38 is subsequently rotated from its normal position in which it is shown in the drawing to one or the other of its extreme positions. This rotationof the lever will cause one or the other of the cams H to engage the cam follower 12 and force the cam follower and plunger 13 downwardly. The downward movement of the plunger 13, in turn, will act through the connecting rod 3! to cause corresponding downward movement of the contact operating member 33, and hence will cause contact 63a- 6363b to become opened and contact 61-4510, to become closed. The downward movement of the plunger 13 will also act through the connecting rod 3| to cause corresponding downward movement of the operating rod 8, which latter movement will slip the clutch F, as will readily beapparent from the foregoing description.

, After the lever has been rotated to an extreme position in the manner just described, the contact operating member and associated parts will remain in the positions which they then occupy until the lever is restored to its normal indicating position and the motor M is energized. When this happens, the operating rod will be moved upwardly by the motor and this upward movement will act through the connecting rod 3| to restore the contact operating member to its upper position. When the contact operating member reaches its upper position, contact 6|6'la will become opened and will deenergize motor M, and contact 63a.6363b will again become closed.

The time required to move the contact operating member from its lower position to the position shown after the motor becomes energized will depend upon the motor speed and gear ratio employed, and also upon the length of stroke of the operating rod. The motor speed, if the motor is a direct current motor as shown, can be readily varied by means of a variable resistance in the well-known manner, and the gear ratio can also be readily varied, However, when the motor is a constant speed alternating current motor such as the well-known Telechron motor, and a gear ratio has once been selected, the only way in which the time interval may be varied is by varying the length of stroke of the operating rod. According to my present invention, this latter variation may conveniently be made by loosening the lock nut l and rotating the operating rod in one direction or another. The threads on the contact operating member have the same pitch as the threads on the nut 9, and it will be seen, therefore, that this rotation will cause the cam follower 12 to move closer to or further away from the segment 1!], and hence will vary the distance through which the operating rod will be moved downwardly by the cams "H to thereby vary the distance through which the operating rod must be moved by the motor to move the contact carrier to its upper position following movement of the lever to an extreme position without varying the extreme upper position to which the contact carrier is ultimately moved. It follows, therefore, that time release mechanism embodying my invention can be designed to provide any desired time interval after the motor M becomes energized following movement of the lever to its normal indicating position from either extreme position and the subsequent closing of the time contact 63a63-63b.

The force required to open the contact 63a 6363b will depend upon the setting of the clutch F, which need transmit only enough force to raise the operating rod, the connecting rod 3|, the plunger 13, cam follower l2, and contact operating member 33 against the force of gravity and to supply the slight additional force necessary to operate the contacts. Only a few ounces are required to effect this result, and it follows, therefore, that the load imposed on an interlocking machine lever by the time release mechanism is so small as to be practically negligible. It should also be noted that this force will only be imposed on the lever after the time release mechanism has been energized to initiate a timing period, which in actual practice may only occur once in a relatively large number of operations of the lever, the lever during the remainder of the time being entirely free from any load due to the release mechanism.

As was pointed out hereinbefore, one function of a time release mechanism of the type described is to prevent the operator from changing a route in the face of an approaching train in a manner that might result in a dangerous trafiic condition, and in Fig. 5 I have illustrated one arrangement of circuits for effecting the desired control of the release mechanism to effect this result when the associated lever is utilized to control opposing signals SI and S2 for governing traflice movements over a switch S which connects a siding X with a main line track Y. As will be apparent from an inspection of Fig. 5, the track Y is divided, in accordance with standard practice, into an approach section KL and a detector section LM in which the switch is located, and both sections are provided with the usual track circuit including track relays TR! and TR2.

For effecting the desired control of the signals SI and S2, the lever 38 is arranged to be moved between a plurality of positions L, A, B, N, D, E and R, which may for convenience be termed in the order named, a left-hand control position, a left-hand intermediate position, a left-hand indication position, a mid or normal position, a right-hand indication positon, a right-hand intermediate position, and a right-hand control position. Operatively connected with the lever are a plurality of contacts 53, 54, 55 and 55 having associated therewith letters indicating the lever positions in which the contacts are closed. For example, contact 54 is closed when the lever occupies its A position, its B position, or any position intermediate these two positions, while contact 56 is closed when the lever occupies its D position, its E position, or any position intermediate these two positions.

In actual practice the lever 38 will also be provided with other contacts for controlling the signals Si and S2. These contacts and the associated circuits are not shown in the drawing because they are well known and form no part of my present invention. For purposes of my present disclosure, it is sufficient to point out that these contacts will be so arranged that when lever 38 occupies its N or normal position, in which it is shown in the drawing, all signals will be at stop. When, however, lever 38 is moved to its R position, signal SI will then be moved to its clear position to permit a train to enter the main track Y from the siding X, whereas when the lever 38 is moved to its L position, the signal S2 will then be cleared to permit a train to proceed on the track Y past the switch, or to enter the siding X, depending upon whether the switch S then occupies its normal or its reverse position.

It will be understood that the lever 38 will be included in an interlocking machine, and will be mechanically interlocked with a lever, not shown, for controlling the switch S in such manner that the switch lever cannot be operated to reverse the switch except when the lever 38 occupies its N or normal position in which all signals will be at stop.

Also associated with the lever 38 is a lever lock comprising a locking segment 50 secured to the lever and cooperating with a locking dog 5| controlled by a lock magnet 52. The parts are so arranged that when the lever is moved to its L or R position, the dog 5! will drop by gravity behind one or th other of two shoulders 501) or 50a formed on the locking segment, and will thus act to prevent the lever from being subsequently moved toward its normal position past the intermediate indication position B or D unless the magnet 52 is energized, in which event the dog 5! will be lifted clear of the shoulders. Electric locks of the type described are in widespread use, and their detail construction is too well known to require further discussion.

The magnet 52 of the lever lock is provided with an nergizing circuit which passes from terminal B of a suitable source of current through time contact 63a6363b of the time release mechanism TRM, contacts 53 and 54 of lever 33 in parallel, and the winding of magnet 52 to terminal C. It will be apparent, therefore, that magnet 52 will become energized, and will attract the dog 51 to unlock the lever whenever the lever is moved from either its L or R position to a position in which the contact 53 or 54 is closed provided contact 83a6363b of time release mechanism TRM is then closed.

The motor M of the tim release mechanism TRM is provided with an energizing circuit which passes from terminal B through front contact 44 of a relay H, an adjustable resistance G, contact 5l-E'!a of device TRM, and the motor M to terminal C. This circuit will become closed whenever relay H becomes energized and closes its 5 front contact 44 provided the contact 61--6la of the device is then closed, and the circuit is so arranged that when it becomes closed motor M will operate in th proper direction to close the time contact 63a time interval has expired. The time required to close this contact can be readily varied by adjusting resistance G to vary the speed of the motor.

The relay H, in turn, is provided with an energizing circuit which passes from terminal B through back contact 45 of track relay TRI, front contact 46 of track relay TRZ, contacts 55 and 55 of lever L connected in multiple, and the winding of relay H to terminal C. It will be seen, therefore, that relay H will become energized when and only when section KL is occupied, section LM is unoccupied, and lever 38 occupies any position but its two extreme positions or its normal position.

In explaining the operation of the apparatus as a whole, I will assume that the operator, having cleared signal S2 to permit a train to proceed on the main track past the switch S by moving lever 38 to its L position, decides, after the train 8363b after the necessary has entered the approach section Y, to change the route and cause the train to enter the siding X. To effect this change, the operator will first move the lever 38 to its B position in which position its movement will be arrested by engagement of the dog 5| with the shoulder a of the locking segment 50. As soon as the lever has been moved to its A position signal S2 will move to its stop position. Furthermore, contact will become closed, and since track relay TB! is then deenergized due to the presence of the train in section KL, the closing of this contact will complete the circuit for relay H. Relay H will therefore become energized and will cause motor M to initiate the operation of the time release mechanism. If the train is traveling sufliciently slowly, the time release mechanism will complete its time interval and close contact 63a-63--63b before the train reaches section LM, and under these conditions magnet 52 will become energized and will unlock the lever 38 by moving dog 5! out of engagement with shoulder 50a of lock segment 50. When this happens, the lever 38 is then free to move to its N position, and the operator will therefore move the lever to this position. This movement will actuate the mechanical locking between the lever 38 and the lever which controls switch S to unlock this latter lever, and as soon as this latter lever becomes unlocked, the operator will actuate it to reverse the switch S. As soon as the switch reaches its reverse position, the operator will then restore lever 38 to its L position, which will clear signal S2 to permit the movement of the train into the siding. This latter movement of the lever 38 will also open contact 63a6363b of the time release mechanism, and will condition the time release mechanism for a new timing period in a manner which will be readily understood from an inspection of the drawings and from the foregoing description. It should be noted that when the release mechanism has completed its timing period, the resultant opening of contact 6l6la will deenergize motor M.

If, under the conditions just described, the train is traveling at such a high speed that it enters section LM before contact B3a--6363b of time release mechanism TRM became operated, the resultant deenergization of track relay TRZ will interrupt the circuit for relay H, and this relay will become deenergized and will stop the operation of the time release mechanism, thereby preventing magnet 52 from becoming energized. In this event, the operator will be prevented from moving the lever past its B position, which will prevent him from making a route change. The time required for the time release mechanism to close its contact E3a-5363b will usually be adjusted with reference to local conditions and the signaling layout, and will be such that if the lever 38 has been moved to its B position and the signal has gone to stop and the contact 6311-63-63!) becomes closed while the train is still in section KL, the train will have had adequate opportunity to stop by the time it has reached signal S2. It follows, therefore, that with the arrangement shown the time release mechanism is efiective to prevent an operator from throwing the switch under a train or in the face of an approaching train.

It should be particularly pointed out that with the release mechanism constructed in the manner described, it will only be set into operation when the lever is moved away from an extreme R or L position while a train is in the approach section, and it follows, therefore, that with the circuit arrangement shown after the lever has once been moved to an extreme position following operation of the release, the release mechanism will not have any effect whatever upon subsequent movements of the lever under normal conditions.

The necessary energization of the magnet 52 to permit normal operation of the lever is effected by suitable circuits not shown in the drawings. These circuits are well known and form no part of my presentinvention.

Referring now to Fig. 6, I have here shown a modified form of time release mechanism in which the motor M has been replaced by a stepping magnet Ml secured to the top plate I. The magnet Ml actuates a pivoted armature 15 which carries a pawl 16. The pawl 16 cooperates with a ratchet wheel 'l'l secured to pinion I9 in such manner that each time the magnet becomes energized, the pawl will be stepped ahead one tooth. The ratchet Wheel is retained in each position to which it is stepped by the armature by means of a retaining pawl 18.

The magnet MI is arranged to be supplied with current impulses over a circuit which passes from terminal B, front contact 44 of relay H, contact 61-61a of the mechanism TRM, a contact IQ-19a of code transmitter CT, and the winding of magnet Ml to terminal C. The code transmitter may be of any suitable type which when energized will cause current impulses to be supplied to the magnet Ml provided relay H is then energized. As here shown, this transmitter comprises an alternating current motor 80 which is constantly supplied with current from the terminals XA and A of a suitable source, and which drives a cam wheel 8|. The cam wheel 8| actuates the contact finger 19 to alternately open and close the contact 19-4 9a.

The relay H is controlled by the lever 38 and the track relays TR! and TR2 in the same manner as in Fig. 5.

In operation, the release mechanism shown in Fig. 5 becomes energized whenever relay H becomes energized, if contact til-61a is then closed, that is to say whenever lever 38 is moved from its L toward its N or its R to its N position while section LK is occupied, and is effective after the necessary time interval has expired to energize the lock magnet 52 and thus render the lock ineffective.

After the time interval has been completed or partially completed, and the lever is subsequently moved to either extreme position the operating rod 8 will be restored to its control position by cam action in the same manner as with the release mechanism shown in Figs. 1 and 2.

Although I have herein shown and described only two forms of time release mechanisms embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. A time release mechanism comprising a contact operating member movable between an initial and a timing position, a contact operated by said member when it reaches its timing position, a connecting rod adjustably connected to said contact operating member, a crank arm, an operating rod adjustably connected at one end to said crank arm and connected at the other end to said connecting rod in such manner that adjustment of said operating rod relative to said arm will correspondingly adjust said connecting rod relative to said operating member, a friction clutch, motor means connected with said crank arm through said friction clutch for moving said contact operating member from its initial to its timing position, a plunger cooperating at one end with said connecting rod, and cam means cooperating with the other end of said plunger and effective when actuated to restore said contact operating member to its initial position, said clutch being adjusted to slip during said restoring movement.

2. A time release mechanism comprising a frame provided at its upper end with an opening, a motor mounted in said frame, a crank arm mounted in said frame, means including a friction clutch for connecting said motor with said crank arm, a nut pivoted to said crank arm, a vertically reciprocable operating rod adjustably screwed through said nut and extending into said opening, a guide provided with intersecting vertically extending slots and with an integral bearing sleeve the lower end of which extends into said opening, a connecting rod slidably mounted in the lower end of said bearing sleeve and connected with said connecting rod in such manner that said connecting rod is constrained to both rotate and move vertically in response to corresponding movements of said operating rod, a tubular contact operating member slidably mounted in the upper end of said bearing sleeve and adjustably screwed onto said connecting rod by threads having the same pitch as the threads in said nut, said contact operating member being prevented from rotating by means cooperating with one of the slots in said guide, contacts operating by said contact operating member when it is moved to an upper position by said connecting rod, a plunger extending into said contact operating member and engaging said connecting rod, a cam follower provided on the free end of said plunger and slidably mounted in said one slot in said guide, and a cam segment mounted to swing in the other slot in said guide and provided with a cam which cooperates with said cam follower to move said contact operating member from its upper position to a lower position which depends upon the adjustment of the adjustable parts.

WILLIAM C. MCWHIR'I'ER. 

